Answer
$\dfrac{25}{x}$
Work Step by Step
Using the laws of exponents, the given expression, $
\dfrac{(5x^3)^2}{x^7}
,$ simplifies to
\begin{array}{l}\require{cancel}
\dfrac{5^{1(2)}x^{3(2)}}{x^7}
\\\\=
\dfrac{5^{2}x^{6}}{x^7}
\\\\=
25x^{6-7}
\\\\=
25x^{-1}
\\\\=
\dfrac{25}{x^1}
\\\\=
\dfrac{25}{x}
.\end{array}
